Prosthetic valve holders, systems, and methods

ABSTRACT

Valve holders and introducers for delivering a prosthetic heart valve to an implant site are configured to facilitate insertion of prosthetic valves through small incisions or access sites on a patient&#39;s body. The valve holders can also be configured to reduce or eliminate the occurrence of suture looping or other damage to the prosthetic valve during implantation. A valve holder according to embodiments of the invention includes features that reduce or eliminate mistakes during implantation of the prosthetic valves, such as a handle that prevents implantation of the valve prior to proper deployment or adjustment of the holder. An introducer is provided which can facilitate temporary deformation of a nitinol prosthetic valve to pass between adjacent ribs of a patient without rib spreading. Valves are provided having a wireform and stiffener band made of materials that exhibit superelastic properties. Valve holders, introducers, and valves according to the various embodiments can be used in minimally invasive procedures, such as thoracotomy procedures.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of U.S. Patent ApplicationNo. 62/620,581, filed Jan. 23, 2018, the entire contents of which ishereby incorporated by reference.

BACKGROUND Field

The present disclosure generally concerns medical devices, deploymentmechanisms, and methods for deploying such medical devices. Morespecifically, the disclosure relates to surgical replacement of heartvalves that have malformations and/or dysfunctions. The presentdisclosure also relates to prosthetic heart valves, and specifically,prosthetic mitral valves, which can be implanted through a minimal-sizedincision. Embodiments of the invention relate to holders forfacilitating the implantation of bioprosthetic replacement heart valvesat native heart valves, for example, for a mitral valve replacementprocedure. Embodiments of the invention also relate to methods of usingthe holders to facilitate implantation of prosthetic heart valves.

Description of Related Art

Referring first to FIG. 1, the human heart is generally separated intofour pumping chambers, which pump blood through the body. Each chamberis provided with its own one-way exit valve. The left atrium receivesoxygenated blood from the lungs and advances the oxygenated blood to theleft ventricle through the mitral (or bicuspid) valve. The leftventricle collects the oxygenated blood from the left atrium and pushesit through the aortic valve to the aorta, where the oxygenated blood isthen distributed to the rest of the body. Deoxygenated blood from thebody is then collected at the right atrium and advanced to the rightventricle through the tricuspid valve. The right ventricle then advancesthe deoxygenated blood through the pulmonary valve and the pulmonaryarteries to the lungs to again supply the blood with oxygen.

Each of the valves associated with the chambers of the heart are one-wayvalves that have leaflets to control the directional flow of the bloodthrough the heart, and to prevent backflow of the blood into otherchambers or blood vessels that are upstream of the particular chamber.For example, as described above, the mitral valve controls the flow ofoxygenated blood from the left atrium to the left ventricle, whilepreventing blood flow back into the left atrium. The valves are eachsupported by an annulus having a dense fibrous ring attached eitherdirectly or indirectly to the atrial or ventricular muscle fibers. Whena valve become diseased or damaged, leakage or regurgitation may occur,where some of the blood travels back upstream through the diseased ordamaged valve, and the efficiency and/or general functionality of theheart may be compromised.

Various surgical techniques can be performed to repair or replace adiseased or damaged valve. In some valve replacement procedures, theleaflets of the diseased or damaged native valve are first removed toprepare the valve annulus for receiving the prosthetic replacementvalve. FIG. 2 shows an example of one type of popular prostheticreplacement valve 1 that is a tissue-type bioprosthetic valve generallyconstructed with natural-tissue valve leaflets 2, made for example, fromporcine tissue or bovine pericardium, or from synthetic leaflets, thatare mounted on a surrounding valve stent structure 3. The shape andstructure of the leaflets 2 is supported by a number of commissure posts4 positioned circumferentially around the valve stent structure 3. Inthese valves, a biocompatible cloth-covered suture or sewing ring 5 canalso be provided on an inflow end of the stent structure 3 of the valve1, to facilitate easier attachment to the native valve annulus. Suchprosthetic valves function much like natural human heart valves, wherethe leaflets coapt against one another to effect the one-way flow ofblood.

When implanting a tissue type prosthetic valve as described above at anative valve annulus, a number of sutures may be involved in theattachment process, many of which may be pre-installed for providing atrack on which the valve is advanced to and properly positioned at theimplant site. Additional sutures may also be applied between theprosthetic valve and the heart walls after proper placement, to securelyattach or hold the valve implant in place. Meanwhile, in some cases, theprosthetic valves are implanted through small access channels using oneof various minimally invasive surgical procedures, where visibility atthe implant site may be impeded or obstructed. In addition, depending onthe direction of implantation, for example, with some mitral valvereplacement procedures, commissure posts of the stent or frame, or otherportions, of the prosthetic valve may be pointed distally and advancedon a blind side of the valve, thereby obstructing visibility of theposts or other portions during advancement and implantation.

Each of the above factors may lead to tangling of the sutures with thevalve prosthesis, most commonly with the commissure posts of the frame,since the commissure posts provide a protrusion on which the sutures caneasily loop around and tangle. This type of entanglement of sutures withprosthetic valves is referred to as “suture looping,” which specificallyrefers to instances where a suture is inadvertently wrapped around oneor more of the commissure post tips, where it can then migrate towardsand damage the leaflets or interfere with proper leaflet coaptation orother valve operation when the sutures are tightened or secured,resulting in improper valve operation. In some cases, such tangling maynot be apparent to the practitioner at the time of implantation, andwill only be revealed some time later when valve operation is observedto be improper or other complications arise in the patient, in whichcase, it may be necessary to initiate another procedure to repair orreplace the prosthetic valve.

In addition, many existing bioprosthetic valves are not amenable toimplantation through a minimal-size incision, such as in thoracotomyprocedures. Such procedures can require a surgical valve and its holderto fit through incisions of approximately 15-20 mm in its narrowestdirection.

SUMMARY

Attempts have been made to resolve the issue of suture looping, some ofwhich involve holders that hold the prosthetic valves during delivery ofthe valves to the native valve annulus. In one example, a holder has amechanism that urges the commissure posts of the prosthetic valveradially inwardly during delivery, such that the ends of the commissureposts are pointed inwards, to reduce the possibility of sutures catchingagainst or looping around the commissure posts. After the valveprosthesis is delivered to the implant site, the holder is removedthereby releasing and expanding the commissure posts to their originalpositions. However, such holders may not be amenable to minimallyinvasive surgical techniques as the holder and valve combination mayhave a high or large profile, for example with the entire holder systempositioned outside the valve, or the holder may not pull in thecommissures enough to reduce the valve profile.

Meanwhile, Edwards Lifesciences has developed a valve holder system thatcan be used in mitral valve replacement procedures to protect the valvefrom suture looping during valve implantation. The system includesmonofilament sutures that attach to both the holder and the commissuresof the prosthetic valve, so that the sutures run over the outflow end ofthe valve between the ends of the commissures. When the holder isactuated, a central post extends distally through the prosthetic valvebetween the leaflets and pushes against the sutures that run across themiddle of the valve between the commissures, pushing the suturesdistally and causing an angled tent-like or “umbrella” effect on thesutures. The pressure on the sutures deflects the commissures slightlyinwardly, while also forming angled surfaces or tracks with the suturesthat slope outwardly from the central post to the commissure posts.These angled surfaces deflect any other sutures that might otherwise belooped over a commissure or leaflet away from the prosthetic valve.However, this system may not be very amenable to a minimally invasivesurgical approach. The system does not pull in the commissures enough toreduce the valve profile, and the central post of the holder adds to theoverall height of the valve once deployed, hindering minimally invasivesurgical procedures.

In addition to the above, many of the newer holder designs alsoincorporate many additional parts that must be assembled by thepractitioner or other end user, which may also lead to additionalcomplications. Some holders incorporate various mechanisms and lineconnections, such that a number of additional steps must be taken by thepractitioner to operate the holders correctly. Many of these holdershave proven to be too complicated and/or prone to user error. Forexample, some holders may allow valves to be implanted without requiringthat its mechanism be activated or deployed prior to delivery, forexample, holders that allow delivery without deploying its mechanism tourge the commissure posts radially inward prior to insertion.Consequently, when practitioners use these holders improperly, suturelooping still commonly occurs, while the implant process may also befurther complicated by issues arising from user error. Further, someholders may require the practitioner to manually adjust the tighteningof the holder to the prosthetic valves. Tightening too little can makethe holder ineffective to prevent suture looping, while over-tighteningcan risk breaking one or more sutures of the system or damaging thevalve.

Accordingly, a new replacement valve holder includes built-inmistake-proofing to ensure the anti-suture looping mechanism is engaged.In some embodiments, the new replacement valve holder can be designed toenable surgeons to implant the valve through minimal incisions, such asin thoracotomy procedures.

In one example, to fit through a minimal size incision, such as a 15-20mm incision, a valve and holder combination can be collapsible in atleast one direction. However, such holders and valves may not include amechanism to actively collapse the valve into the reduced sizeconfiguration for delivery. Accordingly, an introducer according toother embodiments of the invention can be used with collapsible surgicalvalves and/or holders to introduce them into narrow surgical incisions,such as thoracotomies.

Features of the present disclosure provide for new holder systems andmethods of using the holder systems, which reduce or eliminate theoccurrence of suture looping or other damage to the prosthetic valvesduring implantation, for example, for mitral valve replacement usingminimally invasive procedures or other procedures. Operation of theholders is also simplified, whereby the valves are prevented from beingimplanted prior to deployment of the holders, for example, via a holderthat automatically activates upon connection of a handle to the holder,thereby reducing or eliminating mistakes caused by user error. Accordingto embodiments, the system cannot be implanted until the handle isattached and activates the system. The holders also provide forintegrated alignment features or other safety features, such thatover-deployment or under-deployment of the holders is prevented.

According to embodiments of the invention, holders for prosthetic valvedelivery reduce or eliminate occurrences of suture looping and/or otherdamage to the valves when the valves are implanted, while the mechanismsfor deploying these features are integrated into the holders in a waythat reduces or eliminates mistakes in use and deployment.

According to embodiments of the invention, the prosthetic valve includesa wireform and stiffener band made of materials that exhibitsuperelastic properties, such as nitinol, so that the stiffener band canbe ovalized to a high degree for delivery through a small surgicalincision. In addition, the holder according to some embodiments includesflexible arms to allow the valve holder to deform along with theprosthetic valve when compressed for insertion through a small incision,such as in minimally invasive procedures.

In some embodiments, a mitral valve holder is provided that uses alinearly movable piston to pull in the commissures of the valve towardsthe center of the valve, thereby eliminating the risk of suture looping.The holder has mistake-proofing features that prevent the physician fromimplanting the valve without engaging the system. For example, attachingthe handle to the valve holder causes the piston to translate andthereby activate the system. The valve holder is prevented from beingimplanted before the handle is attached to the system. In someembodiments, by collapsing or deforming the profile of the valve and thevalve holder, the holder system can allow implantation of the valvethrough a small or minimal incision. According to some embodiments, anintroducer is provided to aid in implanting replacement valves through aminimal size incision, for example, by aiding in collapsing or otherwisereducing the profile of the valve and/or valve holder. The introducercan be used, for example, with mitral and/or aortic surgical valves. Insome embodiments, such an introducer can be relatively short and onlylong enough to pass the valve past a patient's ribs. In otherembodiments, the introducer can be relatively long and, for example, actas an atrial retractor, forming a channel all the way to the implantsite in the case of a mitral valve.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the invention will become apparentfrom the description of embodiments using the accompanying drawings. Inthe drawings:

FIG. 1 shows a schematic cross-sectional view of a human heart;

FIG. 2 shows a schematic perspective view of an example of a prostheticvalve that can be used with embodiments of the invention;

FIG. 3 shows an exploded perspective view of a valve holder for aprosthetic mitral valve according to an embodiment of the invention;

FIG. 4 shows a perspective view of the valve holder of FIG. 3 in anassembled state;

FIG. 5 shows a cross-sectional view of the valve holder of FIGS. 3 and4;

FIG. 6 shows a perspective view of the valve holder of FIGS. 3 to 5 inan assembled state with a prosthetic valve;

FIGS. 7A to 7B respectively show a perspective view and across-sectional view of a body of the valve holder of FIGS. 3 to 5;

FIGS. 8A to 8B respectively show a perspective view and across-sectional view of an insert of the valve holder of FIGS. 3 to 5;

FIGS. 9A to 9B respectively show a perspective view and across-sectional view of a piston of the valve holder of FIGS. 3 to 5;

FIG. 10 shows a cross-sectional view of the valve holder of FIGS. 3 to 5in an un-deployed configuration;

FIG. 11 shows a cross-sectional view of the valve holder of FIGS. 3 to 5in a deployed configuration;

FIG. 12 shows a perspective view of the valve holder of FIGS. 3 to 5 ina deployed configuration with the insert removed;

FIG. 13 shows a perspective view of an introducer for use with a valveholder;

FIG. 14 shows a front view of the introducer of FIG. 13; and

FIG. 15 shows a perspective view of the valve holder of FIGS. 3 to 5 inuse with the introducer of FIGS. 13 and 14.

DETAILED DESCRIPTION

Disclosed herein are various tools, such as valve holders andintroducers, for assisting in the delivery and implantation ofprosthetic heart valves, such as mitral heart valves, at an implantsite. Disclosed are also methods for preparing the prosthetic heartvalves for such procedures. Also disclosed are valves having a wireformand stiffener band made of materials that exhibit superelasticproperties, such as nitinol, so that the stiffener band can be ovalizedto a high degree for delivery through a small surgical incision.Embodiments of the valve holders and valves reduce occurrences ofvarious complications that may arise during implantation, whileremaining simple for end users to use. By providing these improved valveholders and valves, damage to the prosthetic valves during surgicalprocedures can be reduced, and additional costs for extended oradditional procedures and/or replacement valves can be avoided.

The valve holders disclosed herein are particularly useful for avoidingsuture looping and other valve damage during advancement of theprosthetic valves to the implant sites, as well as during final suturingof the valves at the native valve annulus. In many existing mitral valvereplacement procedures, commissure posts of the prosthetic valve pointdistally away from practitioners, and in the direction of valveadvancement and may be more prone to suture looping or other entangling.For such procedures, valve holders according to embodiments of theinvention can urge the commissure posts radially inwards toward a centerof the valve to reduce or eliminate suture looping. The presentedembodiments can also include features that prevent valve implantationuntil the valve holders are in the activated or deployed positions. Theholders can also include alignment features that prevent over-deploymentor under-deployment. In this fashion, the holders provide ease of usewhile minimizing user errors.

The disclosed mitral valve holder and handle system is specificallydesigned to address shortcomings in previous valve holders. Thedisclosed system prevents clinicians from forgetting or neglecting todeploy the system by means of a handle that deploys the valve holderupon attachment of the handle. Specifically, the disclosed valve holdersystem deploys automatically when the clinician attaches the handle tothe valve holder, thereby preventing implantation before the system isdeployed. The valve holder is unable to be implanted until the handle isattached, thereby enhancing safety of surgical procedures. In addition,the disclosed system becomes fully deployed upon attaching the handle,thereby preventing under-deployment or over-deployment of the system anddamage to the valve or the sutures. As such, attachment of the handle tothe valve holder provides mistake-proof deployment of the system as anautomatically-deploying suture looping protection mechanism. Themechanism deploys when the handle is attached to it, thereby eliminatingextra steps of deployment of the valve and adding a degree ofmistake-proofing. Further, the disclosed valve holder allows the valveto be compressed to fit through a minimal size incision such as athoracotomy. The prosthetic valve, for example, a prosthetic valve thatis structurally similar to the prosthetic valve shown in FIG. 2, can bemade of a nitinol wireform and nitinol stiffener band exhibiting a largeamounts of flexibility to temporarily compress or deform the valve tofit through a minimal size incision.

FIGS. 3 to 6 show views of a valve holder 100. FIG. 3 shows an explodedperspective view of the valve holder 100, FIG. 4 shows a perspectiveview of the valve holder 100 in an assembled state, FIG. 5 shows across-sectional view of the valve holder 100 in the assembled state, andFIG. 6 shows a perspective view of the valve holder 100 in the assembledstate with an attached prosthetic valve.

The valve holder 100 includes a body 102, an insert 104, a piston 106, ashaft 108, and a suture mount 110. As described in more detail below, aprosthetic heart valve can be attached to the body 102. The insert 104is positioned in a bore of the body 102 and connectable to a handle 112to deploy or activate the valve holder 100 to adjust the prostheticvalve to a delivery or implantation position. The piston 106 is attachedto the body 102 and to the insert 104. The piston 106 is movable from afirst configuration where the valve holder 100 is un-deployed forconnecting the prosthetic valve to the valve holder 100, to a secondconfiguration where the valve holder 100 is deployed for implantation ofthe prosthetic valve in a heart of a human body. The shaft 108 is forconnecting the piston 106 to the suture mount 110. The suture mount 110is for routing sutures used to connect the valve holder 100 to theprosthetic valve.

The body 102 of the valve holder 100 is shown in further detail in FIGS.7A and 7B. The body 102 includes a generally cylindrically-shapedcentral hub 114 having a central axis, and a plurality of arms 116extending from the central hub 114. The central hub 114 extends from afirst proximal end 102 a of the body 102 to a second distal end 102 b ofthe body 102. The arms 116 serve as routing points for connectingcommissure posts of the prosthetic valve to the valve holder 100 viasutures or other flexible material. The arms 116 are flexible and hingedrelative to the central hub 114, and may be utilized as flexible livinghinges during implantation. The flexible arms 116 allow the valve holder100 to deform along with the prosthetic valve when compressed forinsertion through a small incision, such as in minimally invasiveprocedures. In particular, the arms 116 are able to flex inward towardsthe hub 114, and laterally in some cases, to accommodate an ovalizationof the valve as it is passed through a small surgical opening. Thereby,the valve and valve holder are able to pass through an opening about thesize of a typical thoracotomy procedure without rib spreading, which maybe approximately 20 mm in the narrowest direction. The flexible arms 116may be resilient such that the flexible arms 116 may be deformed to fitthrough a small incision, and return to their original shape when thevalve and valve holder 100 pass through the small incision.

In the embodiment shown, the body 102 includes three arms 116, but caninclude more or fewer arms 116 in other embodiments depending on theprosthetic valve the valve holder 100 is intended to hold. The number ofarms 116 generally corresponds to the number of commissure posts on theprosthetic valve. When three arms 116 are included in the body 102, thearms 116 can be positioned around the body 102 at approximately 120degrees relative to each other.

Each of the arms 116 includes one or more through holes or bores 118 forrouting sutures connecting the valve holder 100 to the prosthetic valve.As will be further described below, the sutures are used to deploy oractivate the valve holder 100 and place the valve in a delivery positionwhere the commissure posts are urged radially inwards toward a center ofthe valve to reduce or eliminate suture looping. The through holes 118extend transversely through the arms 116. The through holes 118 routethe sutures across the top of the arms 116 (as illustrated) to a regionbelow the arms 116 where the sutures can connect to tips of thecommissure posts, for example, by passing the sutures over and/orthrough other portions of the valve. Multiple through holes 118 can beprovided. Through holes 118 a located near free ends of the arms 116 areused to route and position the sutures for connection to the commissureposts. Through holes 118 b closer to the central hub 114 can be used tofasten or tie off an end of the sutures to the body 102, and tofacilitate easier release of the valve from the valve holder 100. Insome embodiments, through holes 118 c on the central hub 114 may furtherbe provided to facilitate easier release of the valve from the valveholder 100.

Referring to FIG. 6, the valve holder 100 may be connected to theprosthetic valve via sutures as follows. An end of the suture isfastened to the arms 116, for example, via a knot, and routed into thethrough holes 118 a of the arms 116 near the free ends of the arms 116.The ends of the arms 116 are attached to the sewing ring of the valvevia the suture, such that the flexible arms 116 can serve as livinghinge areas to be compressed for implantation in minimally invasivesurgical procedures. As shown in FIG. 6, the ends of the arms 116 may berespectively attached to the sewing ring of the valve at a singlelocation. This attachment method, unlike previous valve holders whichrequire two attachment points at each location, allows the arms 116 topivot on the sewing ring when the system is deformed. The sutures arerouted through the sewing ring of the valve, connected to the commissureposts of the valve, and routed through channels 109 of the suture mount110. The sutures are then routed back through the valve and into throughholes 118 b, 118 c located on or near the central hub 114. In someembodiments, a different number of through holes 118 can be provided foreach suture, and in some embodiments, only one through hole 118 isprovided for each suture, located on each respective arm 116.

An individual suture may be routed through both through holes 118 b and118 c to provide a quick and easy method for removal of the valve fromthe valve holder 100 (see FIG. 12). At the first end 102 a of the body102, an upper surface of the central hub 114 includes a recess or slot120 between the through holes 118 b and 118 c. The sutures extend acrossthe recesses 120 such that there is a clearance underneath the suturesin the region of the recesses 120 to provide space for cutting thesutures. Cutting the sutures at the region of the recess 120 willrelease the valve from the valve holder 102. For example, when threearms 116 and three sutures are provided, the three sutures can be cut inthe region of the recesses 120 to release the valve. If the valve is inthe delivery position, cutting the sutures will also allow thecommissures to spring back to a normal or unbiased geometry by releasingthe commissure posts.

In use, the valve is designed to be placed over and/or around the secondend 102 b of the body 102 such that the body 102 is inserted into thevalve. At the first end 102 a, a bore 122 is provided in the central hub114 for receiving the insert 104 therein. The bore 122 extends from thefirst end 102 a and towards the second end 102 b. Two through holes 118d are provided at the first end 102 a for connecting the insert 104 tothe central hub 114 via a single suture. A single suture connection tothe insert 104 allows for quick and easy removal of the insert 104 fromthe body 102 by cutting the suture (see FIG. 6). At the second end 102b, an opening 124 is provided to allow a portion of the piston 106 toextend therethrough. An outer surface of the central hub 114 at thesecond end 102 b may be tapered (e.g., may have a width or diameter thatincreases in a direction towards the first end 102 a) to facilitatemounting of the valve or passing of the central hub 144 through thevalve. The second end 102 b additionally includes engagement portions126 for connection to locks 128 of the piston 106. Each of theengagement portions 126 of the body 102 includes a channel 126 a and anotch or protrusion 126 b to facilitate engagement of the locks 128 ofthe piston 106, as further described below. The number of engagementportions 126 matches the number of locks 128 of the piston 106. In theembodiments shown, two engagement portions 126 and two locks 128 areprovided. However, it should be appreciated that the number ofengagement portions 126 and locks 128 may be varied in otherembodiments.

The insert 104 of the valve holder 100 is shown in further detail inFIGS. 8A and 8B. The insert 104 has a generally cylindrical shape with aflange 128 at a first proximal end 104 a. The flange 128 includes twothrough holes 130 for communicating with the through holes 118 d of thebody 102 to connect the insert 104 to the body 102 via a single suture.The flange 128 may cover the other sutures discussed above that hold thebody 102 to the valve, thereby preventing the holder 100 from beinginadvertently or unintentionally released from the valve when, forexample, releasing the insert 104 and the handle 112 from the body 102.

The insert 104 further includes a central opening 132 that extendsthrough the insert 104 from the first proximal end 104 a to a seconddistal end 104 b, and a central axis. The insert 104 is configured to bereceived in the bore 122 of the body 102 such that the central axis ofthe insert 104 is aligned with (e.g., collinear with) the central axisof the body 102. The second end 104 b of the insert 104 is designed toreceive the piston 106 therein. The second end 104 b includes slots orchannels 134 extending towards the first end 104 a to provide clearancefor the locks 128 of the piston 106. The number of slots 134 matches thenumber of locks 128 of the piston 106. The insert 104 additionallyincludes an unthreaded lead-in portion 136 a at the first end 104 afollowed by a threaded portion 136 b for connection to the handle 112.The threaded portion 136 b extends towards the second end 104 b. Theunthreaded portion 136 a acts as a guide when inserting the handle 112into the insert 104 to ensure proper alignment between the two partsbefore threading begins. This will greatly reduce the chances ofcross-threading between the parts and generating undesirable particles.In addition, an outer surface of the insert 104 may include a key 138for mating with a keyway 140 of the body 102. The key 138 and keyway 140enable proper alignment of the insert 104 relative to the body 102.

The piston 106 of the valve holder 100 is shown in further detail inFIGS. 9A and 9B. The piston 106 has a generally cylindrical shape from afirst proximal end 106 a to a second distal end 106 b. The second end106 b includes a bore 142 for receiving a portion of the shaft 108therein. An outer surface of the piston 106 at the second end 106 b maybe tapered (e.g., may have a width or diameter that increases in adirection towards the first end 106 a). Meanwhile, the outer surface ofthe piston 106 includes the locks 128 for connection to the engagementportions 126 of the body 102. The locks 128 are provided on flexiblearms 144 of the piston 106 that extend in a direction towards the firstend 106 a. In some embodiments, the locks 128 may be shaped as outwardlyfacing protrusions configured to be received in the channels 126 a ofthe body 102. In some embodiments, the locks 128 of the piston 106 maybe shaped as openings configured to receive inwardly facing protrusionsof the body 102. The flexible arms 144 are spaced apart from theremainder of the piston 106 by gaps 145 on either side of the flexiblearms 144 such that the flexible arms 144 are movable (e.g., bendable)relative to the other parts of the piston 106. The flexible arms 144 maybe bent inwards relative to the other parts of the piston 106 andtowards or into a cavity 146 of the piston 106. The flexible arms 144may be resilient such that the arms 144 can be deflected inwards andthen released, causing the arms 144 to spring back outwards to a relaxedshape when no longer deflected. In addition, the first end 106 a of thepiston 106 includes a bore 148 for connection to a tip portion 152 ofthe handle 112. The piston 106 also includes a central post 150 thatacts as a stop for the tip portion 152 of the handle 112.

The suture mount 110 is used for suture routing. The suture mount 110has a plurality of channels 109 extending from a first end 110 a of thesuture mount to a second end 110 b of the suture mount (see FIGS. 10 and12). The number of channels 109 generally corresponds to the number ofcommissure posts on the prosthetic valve. As described above, eachchannel 109 is used for routing a suture between one of the commissureposts of the valve and the central hub 114 of the body 102. As describedin further detail below, the suture mount 110 may be moved distally(e.g., in a direction away from the first end 102 a of the body 102) tourge the commissure posts downward and radially inwards toward a centerof the prosthetic valve. In addition, the first end 110 a of the suturemount 110 has a bore 111 to connect to the shaft 108. In someembodiments, the suture mount 110 may have a generally spherical shape,but is not limited thereto or thereby.

The shaft 108 is used to connect the piston 106 to the suture mount 110.The shaft 108 may be connected to the bore 111 of the suture mount 110via a press fit, interference fit, through fasteners such as a setscrew, and/or via an adhesive or the like. Similarly, the shaft 108 maybe connected to the bore 142 of the piston 106 via a press fit,interference fit, through fasteners such as a set screw, and/or via anadhesive or the like. It should be appreciate that the shaft 108 may beconnected to the piston 106 via a different type of connection than isused to connect the shaft 108 to the suture mount 110. For example, theshaft 108 may be connected to the piston 106 via an adhesive, and theshaft 108 may be connected to the suture mount 110 via a set screw.

The valve holder 100 may be assembled according to some embodiments asfollows. The piston 106 may be inserted into the body 102 at the firstend 102 a, and moved distally such that the piston 106 extends out ofthe second end 102 b of the body 102. In some embodiments, the suturemount 110 may have a larger diameter or width than the opening 124 ofthe second end 102 b of the body 102, such that the suture mount 110cannot be attached to the valve holder 100 until after the piston 106 isinserted into the body 102. In some embodiments, the piston 106 may bepreassembled with the shaft 108 such that the piston 106 and the shaft108 are inserted together into the body 102. In other embodiments, theshaft 108 may be connected to the piston 106 after the piston 106 isinserted into the body 102. The opening 124 of the body 102 is largerthan the maximum diameter or width of the shaft 108 such that the shaft108 may be inserted therethrough. In some embodiments, the suture mount110 may have a smaller maximum diameter or width than the opening 124 ofthe body 102, such that the piston 106, the shaft 108, and the suturemount 110 may be preassembled, and all three components may be insertedtogether into the body 102. After the piston 106 is inserted into body102 and the shaft 108 and suture mount 110 are connected, the valve maybe connected to the body 102 and the suture mount 110 via sutures asdescribed above. Subsequently, the insert 104 may be inserted into thebody 102 and connected to the body 102 using a single suture asdescribed above. The insert 104 is inserted into the body 102 such thatthe key 138 of the insert 104 is aligned with the keyway 140 of the body102, and such that the slots 134 of the insert 104 are aligned with thelocks 128 of the piston 106. In some embodiments, the slots 134 of theinsert 104 permit translation of the piston 106 relative to the insert104, but restrict or prevent rotation of the piston 106 relative to theinsert 104. Further, in some embodiments, the insert 104 may be insertedinto the body 102 before connecting the prosthetic valve to the valveholder 100.

Referring to FIGS. 10 and 11, the valve holder 100 may be moved betweena first configuration for connecting the prosthetic valve to the valveholder 100, and a second configuration where the prosthetic valve is ina collapsed or delivery position for implantation of the valve.

In the first configuration as shown in FIG. 10, the piston 106 isrecessed relative to the body 102 such that the locks 128 of the piston106 are adjacent or near end portions 134 a of the slots 134 of theinsert 104, for connection to the handle 112 having a tip portion 152and a threaded portion 154. In the first configuration, the handle 112can be inserted into the insert 104 and advanced distally until the tipportion 152 contacts or is positioned in the bore 148 of the piston 106and the threaded portion 154 is adjacent or positioned in the unthreadedlead-in portion 136 a of the insert 104. In other words, the threadedportion 154 of the handle 112 will first reach the unthreaded lead-inportion 136 a of the insert 104 before reaching the threaded portion 136b of the insert 104. The unthreaded portion 136 a helps preventpotential cross threading and particle generation by ensuring axialalignment of the handle 112 and the threaded portion 136 b of the insert104. In some embodiments, the threaded portion 154 of the handle 112 mayhave a thread size of, for example, #10-24 or M5.

When the valve holder is in the first configuration, the handle 112 canbe screwed into the valve holder 100 to actuate the anti-suture-loppingmechanism. In particular, the handle 112 can be screwed in such that thethreaded portion 154 of the handle 112 engages the threaded portion 136b of the insert 104. In so doing, the tip portion 152 of the handle 112will axially press against the piston 106 to cause the piston 106 tomove distally away from the first end 102 a of the body 102. When thesutures are connected to the suture mount 110, the axial movement of thepiston 106 will create tension in the suture lines and cause the suturesto be pulled in the direction of the moving piston 106. Because thesutures are connected to the commissure posts of the prosthetic valve,this distal pulling force activates or deploys the valve holder 100 toadjust the prosthetic value to a collapsed or delivery position bytransferring the force onto the commissure posts of the prostheticvalve. The commissure posts are thereby radially urged inwards toward acenter of the prosthetic valve.

The handle 112 can continue to be screwed into the valve holder 100 toreach a second configuration in FIG. 11, where the locks 128 of thepiston 106 engage the engagement portions 126 of the body 102. Thereby,the locks 128 of the piston 106 will be pressed against the notches 126b of the engagement portions 126 to move into engagement with thechannels 126 a. In some embodiments where the locks 128 of the piston106 include outwardly extending protrusions, the locks 128 will deflectinwards upon contact with the notches 126 b, and snap into the channels126 a. The notches 126 b of the body 102 may have a tapered shapewidening towards the first end 102 b to facilitate deflection of thelocks 128 of the piston 106. In the second configuration, the piston 106is in a fully extended position relative to the body 102 such that thefirst end 106 a of the piston 106 is at a maximum distance away from thefirst end 102 a of the body 102. By the engagement of the locks 128 ofthe piston 106 with the channels 126 a of the body 102 in the secondconfiguration, the piston 106 is prevented or hindered from moving backtowards the first configuration, thereby enhancing safety of the valveholder 100. That is, the engagement of the locks 128 and the channels126 a act as a stop to prevent or hinder relative motion between thepiston 106 and the body 102 while in the second configuration. Safety ofprocedures using the holder 100 is also enhanced because the valveholder 100 becomes automatically deployed when connecting the handle 112to the valve holder 100. In addition, the locations of the piston 106and the suture mount 110 in the second configuration are designed toplace a desired amount of tension in the suture lines to radially urgethe commissure posts of the valve inwards to a predetermined degree.Safety is thus further enhanced by eliminating over-tightening orunder-tightening of the valve. By fully threading the handle 112 intothe valve holder 100 (e.g., by bottoming out the handle 112, or at leastuntil the piston 106 snaps into the second configuration), the valveholder 100 will automatically achieve the desired amount of tighteningof the valve. Meanwhile, safety is further enhanced because the valveholder 100 is prevented from being implanted until the handle 112 isconnected and the valve holder 100 is in the second configuration. Inaddition, the various components of the valve holder 100 can bepreassembled prior to use in surgical procedures, as described above.

Upon implantation to a desired location in a patient, the insert 104 canbe disconnected and removed from the valve holder 100 by cutting thesingle suture connecting the insert 104 to the body 102 (see FIG. 6).Thereby, the handle 112 and the insert 104, which are threadablyconnected, can be removed together from the rest of the valve holder100. Safety of the valve holder 100 is enhanced because the flange 128of the insert 104 blocks the other sutures connecting the valve to theholder 100 to prevent the holder 100 from being inadvertently orunintentionally released from the valve until the insert 104 is removed.Once the insert 104 is removed, final adjustments and implantation stepscan be taken to implant the prosthetic vale at the implant site, and thevalve holder 100 can then be disconnected and removed from the valveafterwards by cutting the sutures connecting the body 102 to the valve(see FIG. 12).

Meanwhile, various different features from the different embodimentsdiscussed above can also be combined into a single modified valveholder. In addition, various other modifications or alternativeconfigurations can also be made to the valve holder according to theabove described embodiments of the invention.

The presented embodiments further include a prosthetic valve exhibitinga large amount of flexibility for use in minimally invasive surgicalprocedures. The prosthetic valve can be made of a wireform and stiffenerband exhibiting large amounts of flexibility to temporarily compress ordeform the valve to fit through a minimal size incision, and revert toits uncompressed state after passing through the minimal size incision.In particular, the wireform and the stiffener band can be made of amaterial exhibiting superelastic properties, such as nitinol. However,other materials may be used that can withstand high amounts of elasticstrain and provide sufficient radial stiffness. In some embodiments, thestiffener band exhibiting superelastic properties can be ovalized to ahigh degree for delivery through a small surgical incision ofapproximately 15-20 mm by 45-50 mm, and the stiffener band can bereturned to it its original circular shape, while maintainingcircularity of the valve during manufacture and after implantation. Suchwireforms and stiffener bands having superelastic properties can be usedin replacement of existing cobalt-chrome or cobalt-chromium (CoCr)wireforms and stiffener bands, which do not permit ovalization fordelivery through minimally invasive procedures.

In some embodiments, a nitinol stiffener band can have the same radialstiffness as existing prosthetic valves utilizing CoCr stiffener bands.For example, nitinol may have an initial elastic modulus that isapproximately 40% of the elastic modulus for CoCr alloys used inprosthetic valves. The resistance to radial force can be matched betweenthe nitinol stiffener band and an existing CoCr band by setting theproduct of their area moments of inertia and their Young's moduli equal.For example, for a 25 mm valve, a CoCr stiffener band may beapproximately 0.0106″ or 0.27 mm thick. Matching the stiffness in theinitial elastic range of nitinol, would result in a thickness of about0.0144″ or 0.37 mm for a nitinol stiffener band based on an assumedYoung's modulus for nitinol that is 40% of CoCr. Such a thickness for anitinol stiffener band does not add significantly to the overall size ofthe valve, and permits the valve to be constructed similarly to existingprosthetic valves that utilize CoCr stiffener bands, while also beingable to utilize a collapsible wireform and stiffener band that can betemporarily collapsed into an oval configuration of approximately 18 mmby 45 mm Such a valve is able to fully recover to a circularconfiguration after passing through an introducer, as described above.In addition, the nitinol stiffener band can incorporate the commissure“towers” used with existing polyester bands, thereby also eliminatingthe need for the polyester bands and simplifying construction.

The disclosed stiffener band can be manufactured from a nitinol sheetusing laser cutting, die cutting, photo etching, or other common methodsof producing 2D parts from sheet material. Subsequently, the 2D partscan be formed into 3D circular parts by heat treatment methods fornitinol. The ends of the nitinol stiffener bands can be joined usinglaser or resistance welding, or could alternatively be temporarilyjoined using an elastic sleeve.

Some of the presented embodiments may also include an introducer whichaids in delivering valve holders in minimally invasive surgicalprocedures. The introducer can be used with the collapsible surgicalvalves having superelastic properties described above to introduce thevalves into a narrow surgical incision, such as a thoracotomy. Theintroducer can be used, for example, for delivering a prosthetic mitralvalve to the mitral position. The introducer has a funnel-like shape forpassing a collapsible heart valve from outside the body to inside thebody through a narrow opening, such as the space between two ribs. Inthoracotomy procedures, an incision is introduced into the chest cavitythrough the chest wall. In intercostal approaches, the incision is madebetween adjacent ribs to minimize cuts through bone, nerves, and muscle.In a typical thoracotomy procedure, the distance between the ribs,without spreading the ribs, is about 15 to 20 mm. Parallel to the ribs,the incision can be longer as needed, for example, approximately 45 mmor greater. Collapsible valve holders can have a small size that isparticularly suited to fit in the small gap between the ribs inthoracotomy procedures.

FIGS. 13 to 14 show views of an introducer 200 for introducing a valveand holder into a human body according to another embodiment. Theintroducer 200 provides a simple approach for implanting collapsibleheart valves connected to flexible holders through a minimal sizeincision, such as in a thoracotomy procedure. Due to the small gapbetween human ribs, the introducer 200 is used as an aid for insertingvalves mounted on flexible holders past the ribs and into the chestcavity during a thoracotomy or other minimally invasive procedures.

The introducer 200 has a hollow, funnel-like shape for receivingflexible holders with mounted valves, with a central axis of the valvespointed in a direction of insertion, for example, with an outflow end ofthe valve pointed or directed towards the introducer 200, as shown inFIG. 15. The introducer 200 has a first, proximal end 202, and a second,distal end 204. The distal end 204 of the introducer faces towards theincision during placement or positioning, while the proximal end 202faces away from the incision and towards the operator of the holder. Theproximal end 202 has a circular cross-sectional shape corresponding tothe circular shape of the prosthetic heart valves. In use, the proximalend 202 is located outside of the incision. In one embodiment, thecross-section of the proximal end 202 is 45 mm in diameter. The distalend 204 has an oval cross-sectional shape corresponding to a size andshape of a surgical opening between ribs in a thoracotomy procedure. Inone embodiment, the major diameter of the cross section of the distalend 204 is 45 mm in diameter and the minor diameter of the cross sectionis 15 to 20 mm in diameter. Between the proximal and distal ends 202,204, the introducer 200 includes a smooth transition zone or region 206connecting the ends 202, 204. The transition region 206 may have asmooth, continuous inner profile between the ends 202, 204, which issubstantially free from corners.

The introducer 200 can be made very inexpensively as a disposable itemthat is supplied with a valve. The introducer 200 can be made of orinclude polypropylene, or any other suitable material having a lowcoefficient of friction. The introducer 200 can be a molded part.Meanwhile, the valve to be implanted can be made of a nitinol wireformband exhibiting a large degree of elasticity. In one embodiment, thevalve exhibits superelastic properties.

In use, the introducer 200 is first introduced into an incision in thechest cavity with the distal end 204 positioned between two ribs. Thevalve, connected to a flexible holder, is inserted into the proximal end202 of the introducer 200, as shown in FIG. 15. The valve is then pushedtowards the smaller, distal end 204 of the introducer 200, where thevalve elastically deforms to squeeze through the smaller cross-sectionalshape. The valve can take on the oval shape of the introducer or anothergenerally collapsed shape as it is pushed through the introducer 200,due to the superelastic properties of the valve. Once the valve clearsthe distal end 204 of the introducer 200, the valve regains itsundeformed shape (e.g., its circular shape). In this way, thedeformation of the valve and holder 100 is passive, being imposed ordictated by the shape of the introducer rather than by a mechanism onthe holder itself. The advantage of this configuration is that theholder can be a very inexpensive molded component.

In one embodiment, a length of the introducer 200 is sufficient tointroduce the valve into an internal surface of the chest wall past therib cage. In such an embodiment, a length of the introducer from theproximal end 202 to the distal end 204 may be up to 40 mm long. In otherembodiments, a length of the introducer can be made longer. In oneembodiment, the distal end 204 could be extended many more centimetersso that it would extend, for example, into the left atrium of the heart,for a mitral valve replacement, to act as an atrial retractor.Meanwhile, the proximal end 202 of the introducer 200 can remainpositioned outside of the incision in the chest cavity. This wouldprovide a tunnel from the outside of the body all the way to the site ofimplantation at the mitral annulus.

In alternative embodiments, the introducer 200 can include variousadditional features, for example, a slit in a wall of the introducer 200can be provided to give clearance for sutures passing through a side ofthe introducer during surgical procedures. In addition, lighting, suchas light emitting diodes (“LEDs”), can be added to the introducer, alongwith a power supply, such as batteries, to power the lighting. LEDlighting can be inexpensively added to the introducer with a built-inbattery. The lighting can be particularly useful with the extendedversion of the introducer. The lighting can provide excellentillumination at the site of implantation and reduce the need foradditional external lighting.

For purposes of this description, certain aspects, advantages, and novelfeatures of the embodiments of this disclosure are described herein. Thedisclosed methods, apparatus, and systems should not be construed asbeing limiting in any way. Instead, the present disclosure is directedtoward all novel and nonobvious features and aspects of the variousdisclosed embodiments, alone and in various combinations andsub-combinations with one another. The methods, apparatus, and systemsare not limited to any specific aspect or feature or combinationthereof, nor do the disclosed embodiments require that any one or morespecific advantages be present or problems be solved.

Although the operations of some of the disclosed embodiments aredescribed in a particular, sequential order for convenient presentation,it should be understood that this manner of description encompassesrearrangement, unless a particular ordering is required by specificlanguage set forth below. For example, operations described sequentiallycan in some cases be rearranged or performed concurrently. Moreover, forthe sake of simplicity, the attached figures may not show the variousways in which the disclosed methods can be used in conjunction withother methods. Additionally, the description sometimes uses terms like“provide” or “achieve” to describe the disclosed methods. These termsare high-level abstractions of the actual operations that are performed.The actual operations that correspond to these terms can vary dependingon the particular implementation and are readily discernible by one ofordinary skill in the art.

In view of the many possible embodiments to which the principles of thedisclosure can be applied, it should be recognized that the illustratedembodiments are only preferred examples and should not be taken aslimiting the scope of the disclosure. Rather, the scope of thedisclosure is defined by the following claims.

What is claimed is:
 1. A valve holder for holding and implanting aprosthetic heart valve comprising a frame and a plurality of flexibleleaflets, the valve holder comprising: a body for holding the prostheticheart valve, the body having a proximal end, a distal end, and a centralaxis extending between the proximal and distal ends; and a pistonconfigured to be positioned at least partially in the body, wherein whenthe prosthetic heart valve is held by the body, the piston is configuredto translate relative to the body along the central axis to adjust theprosthetic heart valve to a delivery position; wherein the piston isconfigured to move relative to the body from a first configuration to asecond configuration, such that the piston is further from the proximalend of the body in the second configuration than in the firstconfiguration.
 2. The valve holder of claim 1, wherein a stop limitstranslation of the piston relative to the body, the stop comprising alock of the piston and an engagement portion of the body.
 3. The valveholder of claim 2, wherein in the second configuration, the piston ispreventing from being moved towards the first configuration by the stop.4. The valve holder of claim 2, further comprising an insert between thebody and the piston, the insert comprising one or more channelsconfigured to engage the lock of the piston to permit translation of thepiston relative to the insert.
 5. The valve holder of claim 4, whereinthe one or more channels of the insert prevent rotation of the pistonrelative to the insert.
 6. The valve holder of claim 4, wherein the bodycomprises a bore configured to receive the insert therein, and whereinthe insert comprises a bore configured to receive the piston therein. 7.The valve holder of claim 1, wherein the body comprises a hub and aplurality of arms, the arms being flexible to allow the body to deformfor insertion into a small surgical opening.
 8. The valve holder ofclaim 7, wherein the flexible arms of the body are configured to deforminwards in a direction towards the hub such that a maximum width of thebody decreases when the arms are deformed.
 9. The valve holder of claim7, wherein the flexible arms are resilient such that the arms areconfigured to deform upon the application of a force and return to theiroriginal shape when the force is removed.
 10. A system comprising thevalve holder of claim 1 and the prosthetic heart valve, wherein theprosthetic heart valve comprises a wireform and a stiffener bandexhibiting superelastic properties.
 11. The system of claim 10, whereinthe stiffener band comprises nitinol.
 12. The system of claim 10,wherein the wireform comprises nitinol.
 13. The system of claim 10,further comprising an introducer for introducing the prosthetic heartvalve into a human body, the introducer having a first end defining afirst opening, a second end defining a second opening, and a channelbetween the first and second ends, wherein the second opening has amajor diameter in a first direction and a minor diameter in a seconddirection that is smaller than the major diameter, wherein the minordiameter is also smaller than both a diameter of the first opening andan undeformed width of the prosthetic heart valve; wherein when theprosthetic heart valve is held by the valve holder and is advancedthrough the introducer from the first end towards the second end, theprosthetic heart valve is elastically deformed via compression in thesecond direction to pass through the second opening of the introducer.14. The system of claim 13, wherein the minor diameter is between 15 and20 mm.
 15. A valve holder for holding and implanting a prosthetic heartvalve comprising a frame and a plurality of flexible leaflets, the valveholder comprising: a body for holding the prosthetic heart valve, thebody having a proximal end, a distal end, and a central axis extendingbetween the proximal and distal ends; an insert for connection to ahandle; and a piston configured to be positioned at least partially inthe body, wherein when the prosthetic heart valve is held by the body,the piston is configured to move relative to the body from a firstconfiguration to a second configuration to adjust the prosthetic heartvalve to a delivery position; wherein the insert is between the pistonand the body, and wherein the insert is configured to threadably engagethe handle to adjust the piston from the first configuration to thesecond configuration.
 16. The valve holder of claim 15, furthercomprising the handle, wherein an opening of the insert comprises athreaded portion configured to mate to a threaded portion of the handle.17. The valve holder of claim 16, wherein the handle comprises anunthreaded tip portion configured to engage an opening of the pistonwhen the threaded portion of the handle is mated with the threadedportion of the insert.
 18. The valve holder of claim 17, wherein theopening extends from a first end of the insert, wherein the openingcomprises an unthreaded portion, and wherein the unthreaded portion isbetween the first end of the insert and the threaded portion of theopening.